1. Field of the Invention
This invention relates to medical instrumentation. More particularly, a tool used for acquiring tissue and a method for using the same are disclosed.
2. Description of the Prior Art
A number of medical procedures require the removal of tissue samples from a patient. These operations can range from the removal of suspicious tissue, as in the biopsy of a cancerous lesion, to cell harvesting, as in a bone marrow donation. A number of different biopsy tools are used for retrieving these tissue samples from patients, falling into two broad categories: Single-Insertion, Single-Sample (SISS) tools and Single-Insertion, Multiple-Sample (SIMS) tools. With an SISS tool, the operator (1) positions the tool; (2) actuates the collection mechanism(s); (3) removes the tool from the patient; (4) removes the sample from the tool; (5) prepares the tool for re-insertion; and (6) inserts the tool into the patient again. This procedure, which may be repeated several times, is time-consuming and traumatic for the patient. SIMS tools can eliminate steps three through six, above.
The mechanisms of SIMS devices are generally more complex and expensive to manufacture than SISS tools. In addition, they are often quite large devices, as a tissue capturing element is often moved fully distally to obtain the sample, then fully proximally to store the tissue sample. Other known devices shorten the device by spiraling the tissue capturing element in the handle. Other known devices use tissue augers to transport the tissue, but these have not yet been employed in a system that can provide large contiguous samples.
Helical, tissue-contacting features can serve many functions in a biopsy tool, from tissue securing to tissue storage. However, an auger system has not yet been employed in a low-cost, easy to use SIMS tool. Moreover, known devices require the internal element to rotate, which typically yields poor sample quality as the internal element must be sufficiently large to transmit the required torque.